1. Field of the Invention
The present invention is generally directed to the field of tubular structures, and, more particularly, to a novel joint design between a tubular component and a connector and a method of welding same.
2. Description of the Related Art
In the oilfield industry, many separate lengths of pipe are coupled together to create, in some cases, very long conduit structures. Such structures may be used for a variety of purposes, e.g., transportation of oil and gas, lining of wells, etc. Typically, each section of pipe is provided with a threaded pin connector (male connector) on one end and a threaded box connector (female connector) on the other end. Pipe sections are coupled to one another by threadingly engaging the pin connector on one tubular with a box connector on another tubular. This process is continued until the desired length of the structure is completed.
In some cases, a section of pipe is provided and the pin and box connectors are welded onto the opposite ends of the pipe. The diameter of the pipe may vary depending on the particular application, e.g., 20″, 26″, 30″, etc. The wall thickness of the pipe may also vary depending upon the particular application, i.e., the wall thickness may vary between approximately 0.438-2.0 inches.
As indicated in FIG. 1, in some cases, the joint 10 between the pipe 12 and the connector 14 was a single bevel joint in which the standard pipe joint bevel of approximately 30 degrees was provided on both components. The longitudinal centerline 13 of the pipe 12 is schematically depicted in FIG. 1 as are exterior surfaces 18 and interior surfaces 20 of the pipe 12 and connector 14. Also depicted in FIG. 1 is a vertical land 15 formed on both the pipe 12 and the connector 14. Typically, the joint 10 was filled by performing one or more welding passes from the outside of the joint 10.
Joining the pipe 12 and connector 14 using the joint 10 configuration depicted in FIG. 1 presented several problems. For example, especially with large diameter piping, obtaining axial alignment between the pipe 12 and the connector 14 was a very difficult and time-consuming process due to a variety of reasons, e.g., the pipe and/or connector being out-of-round, the weight and stiffness of the pipe 12 and connector 14, waviness in the pipe 12, etc. Typically, prior art techniques for axially aligning the pipe 12 and connector 14 might involve welding on various clips and manipulating the pipe 12 and/or connector 14 until such time as the proper axial alignment was achieved. Such manipulation of the components was very difficult due to, among other things, the physical size and weight of the pipe 12 and the connector 14. Thereafter, prior art welding processes often involved tack welding the joint 10 at several locations around the perimeter of the joint 10, followed by performing a MIG welding process to lay down a relatively small weld bead in the joint 10 at the root 19. Thereafter, the joint 10 was completed by performing any of a variety of known welding processes to completely fill the joint 10. Due to the volume of the joint 10, it typically took several passes, i.e., multiple weld beads, to completely fill the joint 10.
The present invention is directed to a device and various methods that may solve, or at least reduce, some or all of the aforementioned problems.